I have been experiencing knee pain after every bike ride for the last 3 weeks .I ride to and from work maybe 3 times a week 45 minutes each way (I also run 4 times during the week for 30 minutes). It has never happened before and it is starting to concern me. My knees are in pain after I ride, then they feel swollen (running seems fine). It usually goes away after a while but the swollen feeling comes back at night (wether I exercise that day or not). Does anyone have any suggestions on how to alleviate this I am leaving on vacation and I need my knees

Since it's on both sides it's presumably some sort of overuse-related problem rather than tweaking something. What exactly it is of course depends on what part of the knee hurts. Runnersworld.com and a couple of other running-related sites (don't recall which ones) have info. pertaining to what the most like problem is for pain in different areas of the knee. I assume there's similar info. on cycling sites but I haven't looked at those enough to know. A common injury among both runners and bikers that I've had a lot of trouble with myself is iliotibial band syndrome, where the pain is usually on the outside of the knee area, and doesn't have anything to do with problems in the knee itself (rather, it's tightness and irritation in the iliotibial band).

In my experience the type of knee pain you describe is usually associated with overtraining the quads, and the hamstrings are unable to counter balance them. This puts a strain on your knee as the quads, even while resting, pull harder on your knee than the hamstrings, thus pulling your knee parts out of alignment.

Try working your hams more. Lunges are good, running backwards, whatever you can think of that strengthens your hams rather than your quads. Over time, you might see an improvement. But bear in mind if it's a muscular imbalance you'll need to give yourself time to let your hams build up strength. Don't expect results overnight if you're been overtraining your quads for years.